Poznámky redaktora
Besides excellent efficiency and
reliability, diode bridges feature high power
factor (typically >0.
VSI
In general, today’s state-of-the-art medium
voltage drive products are based one of
two basic inverter topologies: Voltage Source
Inverter (VSI), employing DC-link capacitor
and providing switched voltage waveform,
and Current Source Inverter (CSI), employing
a DC-link inductor and providing switched
current waveform.
A VSI allows very reliable and highly efficient
input rectifier topology means simple
diode bridge.The evolution ABB’s VSI-MF topology
ABB has been driving the evolution state-of-the-art medium voltage drive
technologies for more than years.
IGCT
In 1996 ABB introduced IGCT (Integrated Gate
Commutated Thyristor) semiconductors, fast
switching power switches that have inherently
low losses.
IGCT-based high-powered medium voltage
drives are ore reliable than edium
voltage drives using IGBTs they require
fewer power semiconductors. For medium voltage applications
such devices led compromises design that
increase cost and complexity high-powered
drives.
Advantages VSI
A VSI can implemented without the need
for additional input output filters, which are
a must CSI topology with self-commutated
semiconductors. In
addition, thyristor rectifier has worse power
factor the supply side and typically needs
additional com pensation equipment. Today, the VSI the
preferred topology the market. Until then the power switches for
medium voltage drives had been either GTOs
or IGBTs.
For more than two decades, ABB has been
pioneering the developm ent VSI-based
medium voltage drives. The CSI topology either
uses thyristor rectifier active rectifier
unit with self-commutated components, which
are inherently less reliable and efficient.
1969
Start drive
development
1985 1993
Megastar 3-level
PWM drive
with vector control
Self-healing
capacitors
1995
Direct Torque
Control (DTC)
1996
Integrated Gate
Commutated
Thyristors (IGCTs)
8 ACS 5000 ABB
.95), which constant over
the whole speed range.
Furthermore, the VSI topology has more
superior dynamic control performance than
the CSI topology
